The present invention relates to a system and method for detecting adverse health conditions based upon analysis of hemodynamic waveforms derived from pressures in a heart.
It is possible to obtain cardiovascular data, for healthcare and research purposes, using an implantable medical device (IMD) such as an implantable hemodynamic monitor (IHM), together with a pressure sensor lead that senses blood pressure within a heart chamber and an electrogram (EGM) of the heart. The IHM senses absolute blood pressure values, and the patient is also provided with an externally worn atmospheric pressure reference monitor record contemporaneous atmospheric pressure values.
A cardiovascular analysis system using the IHM can be programmed to sense and calculate various hemodynamic parameters.
The IHM is programmed and interrogated employing an external programmer or a PC to accumulate trend data at a programmable resolution.
The IHM and the atmospheric pressure reference monitor can transmit by telemetry the sensed and stored pressure and other data to a nearby interactive remote monitor for temporary storage of the data. The interactive remote monitor periodically transmits accumulated data to a remote data processing center that can process the data to develop trend data that the attending physician can review, along with other patient data derived in patient examinations and interviews, to assess cardiovascular health.
Such an IHM system implanted in patients suffering from adverse cardiovascular health conditions can accumulate date-stamped and time-stamped blood pressure data that can be of use in determining the condition of the heart and or vascular system over an extended period of time and while the patient is clinically tested or is engaged in daily activities. Various other IHM functions and uses of EGM, pressure and other parameter data accumulated in an IHM are disclosed in U.S. Pat. Nos. 5,368,040, 5,417,717, 5,564,434, 6,104,949, 6,155,267, 6,280,409, 6,275,707, 6,309,350, and 6,438,408, and U.S. Pat. App. Ser. Nos. 2003/0199779 and 2004/0167410.
Adverse health conditions may include coronary artery disease (CAD) and pulmonary hypertension (PHT) (commonly referred to as PAH). CAD occurs when coronary arteries, which supply blood to heart muscle, become hardened and narrowed due to atherosclerosis, which is a buildup of plaque on inner walls or a lining of arteries. Blood flow to the heart is reduced as plaque hardens and narrows the coronary arteries. This decreases the oxygen supply to the heart muscle, which can lead to numerous heart conditions and heart failure.
PHT occurs when blood pressure in a pulmonary artery rises above normal levels. PHT is associated with an increased resistance to blood flow in blood vessels, which can cause a heart to work harder to try to push blood through those vessels. PHT can be categorized as primary or secondary. Secondary PHT is when a pre-existing disease causes PHT, while primary PHT is when the cause of PHT is unknown and therefore PHT is considered the primary disease.
It is desirable to use an IHM system to monitor cardiovascular condition in order for healthcare providers to provide diagnose illness and to monitor adverse health conditions. Thus, a system and method for detecting health conditions using hemodynamic pressure waveform data is needed.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a cardiovascular analysis system that includes an implantable medical device with a sensor positioned to sense a hemodynamic pressure over time. The implantable medical device generates hemodynamic pressure waveform data based upon the hemodynamic pressure sensed. A processor analyzes the hemodynamic waveform data to provide an indication of cardiovascular and cardiopulmonary health based upon prominent peaks in the hemodynamic waveform data.
The invention further includes a method of cardiovascular analysis. The method includes sensing a hemodynamic pressure, generating a hemodynamic pressure waveform representing the hemodynamic pressure sensed for a cardiovascular pulse cycle, and providing an indication of whether an adverse cardiovascular condition is present based upon a shape of the hemodynamic waveform over a systolic time interval.